1. Field of the Invention
The present invention relates to electronic converters referred to as "self-compensated" electronic converters which are connected to the AC line voltage and provide at an output a high-frequency signal of substantially constant amplitude, while the AC line current remains substantially sinusoidal and in phase with the voltage because of the energy transfer mode recovery of a suitable portion of the previously converted high-frequency energy.
2. Description of the Related Art
The prior art system of this kind which offers the best performance is shown in the accompanying FIG. 1, which shows the most beneficial embodiment of the system claimed in U.S. Pat. No. 5,134,556. In that embodiment, which is representative of the prior art, the output terminal B of the converter A delivers the high-frequency converted energy via a galvanic isolation capacitor C whose capacitance is chosen so that its impedance at said high frequency does not significantly interfere with the resonant frequency of the output oscillatory circuit, which include's the inductor D, the output load E and the phase-shifter capacitor F. Unlike the capacitor C, the capacitor F must have an impedance at the high switching frequency such that the amplitude of the alternating current signal developed between its terminals reaches a chosen value. That signal, applied to one of the non-polarized input terminals of the rectifier bridge I, enables the envelope of a low-frequency rectified signal to be recovered between the terminals of the capacitor H.
The polarized outputs of the rectifier bridge I are connected in series with the polarized outputs of the AC line voltage rectifier bridge J, with the result that said low-frequency envelope between the terminals of the capacitor H is added to the rectified AC line voltage signal, which improves the power factor of the AC line current.